The present application claims the priority of the commonly owned copending German patent application Serial No. 101 32 760.9 filed Jul. 10, 2001. The disclosure of the aforementioned priority application, as well as that of each U.S. and foreign patent, patent application and publication identified in the specification of the present application, is incorporated herein by reference.
The present invention relates to improvements in apparatus for treating fibrous materials of the tobacco processing industry, and more particularly to apparatus for treating surplus-containing streams or flows (such as tows) of filamentary material (such as tobacco shreds, filaments of filter material for tobacco smoke and the like) prior to final processing, e.g., prior to wrapping into webs of cigarette paper or prior to subdivision into stream sections of desired length.
An apparatus for treating one or more streams of fibrous material for use in the tobacco processing industry (e.g., one or more streams of shredded tobacco leaf laminae), for example, for the making of plain cigarettes or filter cigarettes, normally comprises a conveyor for each surplus-containing stream and an equalizing means which includes a discrete surplus removing device for each stream. Each conveyor defines a channel or path for the respective stream and, if the apparatus comprises several conveyors, the channels defined by such conveyors are or can be parallel to each other.
Apparatus of the above outlined character are disclosed in commonly owned U.S. Pat. No. 5,526,826 and in the corresponding German patent No. 43 33 046 A1.
The patented apparatus comprises a surplus removing device having a pair of knives and a deflector for removed fragments of fibrous material. The deflector is provided (a) with a peripheral surface which directs the removed fibrous material away from the trimming knives and (b) with a circular knife at that end of the peripheral surface which is adjacent the trimming knives.
A somewhat similar surplus removing arrangement is disclosed (at 30546) in the September 1989 issue (No. 305) of the RESEARCH DISCLOSURE published by Emsworth Design, Inc. now located at 200 Park Avenue, New York, N.Y. 10003. This surplus removing arrangement employs two surplus removing devices each of which is set up to remove the surplus from the respective one of two discrete tobacco streams. The streams are parallel to each other and one of the two surplus removing devices is located downstream of the other (as seen in the direction of flow of fibrous material along its respective path). The means for deflecting freshly removed fibrous material from the trimming knives of each surplus removing device comprises a rotary brush.
An object of the invention is to provide an apparatus for treating one or more surplus-containing streams which constitutes an improvement over and a further development of the aforediscussed conventional apparatus.
The invention is embodied in an apparatus for treating at least one surplus-containing stream of fibrous material of the tobacco processing industry prior to further processing of the stream. Such further processing can include wrapping the treated stream into a web of cigarette paper or the like to form a continuous tobacco-containing rod, subdividing the rod into sections of unit length or multiple unit length, packing the thus obtained rod-shaped smokers"" products, and connecting the sections with filter mouthpieces to obtain filter cigarettes, cigars or cigarillos prior to packing.
The improved apparatus comprises material advancing means including at least one conveyor defining an elongated channel for advancement of the at least one stream in a predetermined direction, along a predetermined path and at, a predetermined speed. The at least one conveyor includes at least one sidewall and means for moving the at least one sidewall in the predetermined direction and at least close to the predetermined speed. The at least one sidewall includes a stream-contacting surface provided with spaced-apart recesses for portions of the at least one stream, and the apparatus further comprises equalizing means including means for removing the surplus from the advancing stream downstream of the sidewall, as seen in the predetermined direction.
The at least one sidewall can form part of an endless flexible element, e.g., a belt, particularly a toothed belt.
The at least one conveyor can include a plurality of sidewalls, and the means for moving the sidewalls can include means for advancing each of the sidewalls in the predetermined direction and at least close to the predetermined speed. Each sidewall includes a stream-contacting surface. The at least one conveyor can include two sidewalls, and the means for moving can include means for synchronizing the movements of the sidewalls with each other. Each of the stream-contacting surfaces can be provided with spaced-apart recesses for portions of the at least one stream.
The improved apparatus preferably further comprises means for subdividing the equalized stream into a series of discrete sections (e.g., into plain cigarettes of unit length or multiple unit length) and means for synchronizing the operation of the subdividing means with the operation of the moving means. The synchronizing means can include signal generating means which monitors the portions of the at least one stream in the predetermined path.
If the improved apparatus is designed to treat a plurality of surplus-containing streams of fibrous material (such as tobacco or filter material for tobacco smoke), the advancing means includes a plurality of conveyors (one for each of the plurality of streams), and the equalizing means includes a discrete surplus removing means for each of the plurality of conveyors.
The single surplus removing means or each surplus removing means can include a pair of rotary trimming knives having circular severing portions adjacent each other at the single channel or at the respective channel, means for rotating the knives in opposite directions, and means for deflecting the removed material from the knives. The severing portions of the knives are disposed in a plane which is located at a predetermined distance from the at least one conveyor or from the respective conveyor. The severing portions of the knives of each surplus removing means are adjacent to the central portion of the single channel or the respective channel.
The knives of the single surplus removing means or of each surplus removing means are disposed between the single channel or the respective channel and the single deflecting means or the respective deflecting means. The single deflecting means or each deflecting means (depending upon the number of surplus removing means) can comprise a substantially frustoconical rotary deflector for the removed surplus of fibrous material. The peripheral surface of each deflector can include a first portion which is adjacent the knives of the single surplus removing means (or the respective surplus removing means), a second portion which is remote from the knives, and an intermediate portion between the first and second portions. As already mentioned hereinbefore, the knives of the single surplus removing means or of each surplus removing means are or can be disposed in a common plane; the first portion of the peripheral surface of the deflector or each deflector makes with the common plane of the associated knives a relatively small acute angle (e.g., an angle of about 5xc2x0), and the second portion of such peripheral surface makes with the plane a larger angle (e.g., an acute angle of, for example, 40xc2x0, a right angle or an obtuse angle, e.g., an angle of about 120xc2x0). The intermediate portion of the frustoconical surface preferably establishes a gradual transition between the first and second portions of such surface.
The diameter of one trimming knife can exceed the diameter of the other trimming knife of the single surplus removing means or each surplus removing means. Alternatively, the trimming knives of each surplus removing means can have at least substantially identical diameters.
If the improved apparatus is designed to treat at least two at least substantially parallel surplus-containing streams of fibrous material, the material advancing means includes a discrete conveyor for each of the at least two streams and the channels which are defined by the conveyors are spaced apart a predetermined distance from each other. The equalizing means of such apparatus comprises a discrete surplus removing means for each other the streams, and at least one such surplus removing means can include a plurality of rotary trimming knives including a first knife and a second knife disposed between the channels and having a diameter which at most equals the predetermined distance. The knives are or can be round, and the diameter of each second knife can at least approximate the predetermined distance. The knives are preferably provided with smooth (such as non-recessed) peripheral surfaces (cutting edges).
The apparatus can further comprise a novel housing for at least a portion of at least one of the material advancing means and the equalizing means. A presently preferred housing includes at least one extruded section which can consist of or can contain aluminum. The housing is preferably convertible for use with one or more conveyors, and the at least one section can constitute a distancing element which is adapted to be put to use in the housing irrespective of the number of conveyors.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.